Question 263137: After an accident, polie determine the spped at which the car had been traveling based on the length of the skid marks the car left on the road. The police use the following formula: r= 2(over)/(5L)^-1/2, where r is the speed of the car, in miles per housr, and L is the distance of the skid marks, in feet.
A. Solve the equation r= 2(over)/(5L)^-1/2 for L. (Apply rule of negative and fractional exponents before solving for the variable L.)
B. How far will a car skid at 65 mph? Round your answer to the nearest whole, feet if necessary. (Use your equation in 1A and replace the known values in the equation.
Thanks!!!
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! After an accident police determine the speed at which the car had been traveling based on the length of the skid marks the car left on the road.
The police use the following formula: r= 2(over)/(5L)^-1/2, where r is the speed of the car, in miles per hour, and L is the distance of the skid marks, in feet.
A. Solve the equation r= 2(over)/(5L)^-1/2 for L. (Apply rule of negative and fractional exponents before solving for the variable L.)
r= 2(over)/(5L)^-1/2 for L
r = 2(5L)^(1/2)
(5L)^(1/2) = (r/2)
(5L) = (r/2)^2
5L = r^2/4
L = r^2/20
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r is the speed of the car in miles per hour,
L is the distance of the skid marks, in feet.
B. How far will a car skid at 65 mph? Round your answer to the nearest whole, feet if necessary.
L(65) = 65^2/20 = 211.25 ft
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Cheers,
Stan H.
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